Combined indicating fuse post and pilot light



7, 1956 E. v. SUNDT COMBINED INDICATING FUSE POST AND PILOT LIGHT 2 Sheets-Sheet 1 Filed June 14, 1954 IN V EN TOR.

7, 1956 E. v. SUNDT COMBINED INDICATING FUSE POST AND PILOT LIGHT 2 Sheecs-Sheet 2 Filed June 14, 1954 Mar% fl ygi if United States Patent COMBINED ZNDICATING FUSE POST AND PILOT LIGHT The principal object of this invention is to provide a combined indicating fuse post and pilot light wherein a cartridge fuse protects the electric circuit to be protected, wherein a pilot lamp continuously indicates the condition of the cartridge fuse, the lamp being brightly illuminated when electrical power is being supplied to the circuit being protected by the cartridge fuse and being dimly illuminated when the cartridge fuse is blown, wherein the lamp and cartridge fuse are removably carried by a knob member which in turn is removably carried by a body member mounted on a panel or the like, wherein electrical connections are automatically established through the cartridge fuse and lamp when the knob member is removably secured to the body member, wherein the cartridge fuse and lamp may be readily and quickly replaced without danger of electrical shock, wherein the parts are sealed against moisture and dirt, and wherein the combined indicating fuse post and pilot light may be inexpensively and readily manufactured, installed and serviced.

Further objects of this invention reside in the details of construction of the combined indicating fuse post and pilot light and in the cooperative relationships between the component parts thereof.

Other objects and advantages of this invention will become apparent to those skilled in the art upon reference to the accompanying specification, claims and drawings, in which:

Fig. 1 is a perspective view of the combined indicating fuse post and pilot light of this invention;

Fig. 2 is a vertical sectional view through the combined indicating fuse post and pilot light taken substantially along the line 22 of Fig. 1;

Fig. 3 is a sectional view taken substantially along the line 33 of Fig. 2;

Fig. 4 is a sectional view taken substantially along the line 4-4 of Fig. 2;

Fig. 5 is a sectional view taken substantially along the line 55 of Fig. 2;

Fig. 6 is an enlarged sectional view taken substantially along the line 6--6.of Fig. 2;

Fig. 7 is a sectional view taken substantially along the line 7-7 of Fig. 2;

Figs. 8 and 9 are exploded perspective views illustrating the various parts forming the combined indicating fuse post and pilot light;

Fig. 10 is a wiring diagram of the combined indicating fuse post and pilot light.

The combined indicating fuse post and pilot light of nections are automatically established between terminals is inserted through a suitable hole in a panel with the carried by the body member and the lamp and cartridge fuse carried by the knob member to connect the ice cartridge fuse in series with the circuit being protected for protecting the same, to connect the cartridge fuse and lamp in series to brightly illuminate the lamp when electrical power is being supplied to the circuit being protected, and to connect the lamp in series with a resistor to dimly illuminate the lamp upon blowing of the cartridge fuse.

The body member 11 includes a substantially cylindrical hollow body portion 13 formed of electrical insulating material such as a thermosetting plastic of phenol formaldehyde or the like. The inner end of the body portion 13 is closed as indicated at 14 and the closure wall 14 is provided with a central recess 15. The outer open end of the body portion 13 is provided with a shouldered flange 16. The inner surface of the body portion 13 is provided with suitable guide grooves for receiving metallic terminals 18, 22 and 25, which terminals extend through suitable openings in the end closure wall 14 of the body member.

The first terminal 18 is provided with a spring clip 19 and with bent over ears 20, the terminal 18 being secured in the body portion 13 by a tongue 21. The clip 19, formed on the terminal 18, is located centrally of the body portion 12 adjacent the end closure wall 14. The second terminal 22 is provided with bent over ears 23 and is secured in place in the body portion 13 by a tongue 24. The third terminal 25 is provided with a clip 26 and is secured in place in the body portion 13 by a tongue 27. The clip 26 is located substantially midway between the ends of the body portion 13 and this clip 26 is in alignment with the clip 19 and is of larger diameter than the clip 19.

Secured to the open outer end 16 of the body portion 13 is a metallic ring 28. This metallic ring 28 is connected by a resistor 29 to the second terminal 22. The resistor 29 is formed from a strip of thermosetting material and is provided on one side with a resistance coating. The ends of the strip are coated with a silver paint or the like as indicated at 30 and 31, the end 30 being soldered into the terminal 22 behind the cars 23 and the end 31 being soldered to the contact ring 28. A resistor 32 is connected between the first and third terminals 18 and 25. Here also the resistor 32 may be formed of a strip of thermosetting material coated with a resistance material and provided at its ends 33 and 34 with a coating of silver paint or the like. The end 33 is soldered to the terminal 18 behind the ears 20 and the end 34 is soldered to the terminal 25 adjacent the clip 26. The resistance of the resistor 32 is many times greater than the resistance of the resistor 29. For example, the resistor 32 may have a resistance value of about one megohm while the resistor 29 may have a resistance value insulating material is secured in the metallic mounting sleeve 36 with its shouldered end 16 engaging the shouldered end 39. The body member 11, thus formed,

shouldered flange 39 engaging the front of the panel. A nut 41 is then threaded onto the threads 37 for securing the body member to the panel. The hexagonal portion 38 is utilized for holding the body member stationary while the nut 41 is being tightened. Located between the shouldered flanges 16 and 39 of the body member 11 is an O-ring 42 which operates to seal theinterior of the body member 11 when the knob member 12 is removably secured thereto.

The knob member 12 includes a pair of separable .1 parts 45 and 57. The part 45 is formed of electrical insulating material such as a thermoplastic material of nylon or the like. The parttdfi which is generally of hollow cylindrical. configuration-is provided atv one: end. with. a pair. of. grooves. 46 terminating in offset grooves 47 for. forming, a. bayonet join-t.v A metallic. contact sleeve. 48 is secured in thepart 45. and itv is. provided. with grooved projections 49 which are received in the. grooves. 46. The. grooved projections 49 terminate. in slots 50' which are. adjacent the grooves 47 in'the part 45. Thus, the.-. grooved projections 49' and the slots 50 cooperate with. the. grooves 46 and 47 in the. part 45 to. provide. the female. portion of a bayonetjoint... The

other. end of the contact sleeve. 48 is provided. with, a.

flange 51.. which inyturn. isproVidcdWith. aplurality of lockingears 52. The partx45. also. has secured. therein a metallic. sleeve. clip 54 provided with internally directedltongues 515..

The. other part'. of. the knob member 12.. may be formedlfforn a light transmitting electrical insulating, materi'al" such as a thermoplastic material of. polystyrene or, the like. The part 57 is. provided withuan internal cavity 58" which in turn is provided. with an internal groove 59. The part 57'i's also externally provided with screw threads 60" to. be received" in. the. internal. screw threads 40' of the body member 21-1. Thev lockingears. 52" are resiliently forced outwardly by an annular coil spring 61. The parts 45' and 57 are removably secured together by. the locking. ears 52' being resiliently received in. the internal'annular groove 59. Thus, the. parts 451 and 57" may be readily separated and. secured together.

A lamp 62; such as a.neon lamp, is removably mounted' in the. knob member'12I In this .connection,.the lamp. 62 is provided with a sleeve contact 63. which. in turn carries a pair of pins-6.4. The sleeve contact 63'. is received in, the contact. sleeve 48' with the pins passing through the. grooved projections 49" into the. slots 50 for removably securing the lamp 62 in place. Thus, the lamp 62may be readily'replaced in the knob member 12"by merely removing the part 57. The sleeve con- -tact.63'of the lamp makes. electrical contact with the. contact. sleeve 48, either directly or through the pins 642 The l'amp62 is also provided'with a central'contact 65, the. central contact 65 and the sleeve contact 63 forming, a pair. of contacts for the lamp 62'.

The knobmemb'er 12 also removably carries, a con.-v ventionall cartridge fuse 67" having metallic end caps 68f'and69'. The. metallic end .cap. 68ofthe, cartridge time 67' isreceived in the. sleeve clipv 54, firm. electricalcon tact. being. obtained by the interned tongues 5.51 The end" cap 68' of the cartridge fuse 67' electrically con-v tactsthe' centralcontact65 of the lamp. 62, the cartridge.

fuse and thelamp being arranged in endto endf align. ment. end cap 68" of the cartridge fuse 67" and the. central contact 65 of the lamp 62, a spring. 71 is located in the central recess 15. ofthe body member 11' and is inter.-

posed between they end? closure wall 14. and the end other end of this circuit being electrically associated with the power line leading to the second terminal 22$ When the knob-member. 12; carrying the lamp 62 and? the cartridge.v fuse 67, is inserted in the body member '11 by engaging thescrew threads. 46" and 60, the. end...

cap 69of the cartridge fuse67 is receivedinflthe. clip.

19 ofthe terminal 18', the sleeve clip 54 is receivedin the clip 26 of the terminal 25 andthe shoulder. 5.1. on the contact sleeve 48. engages. the, contact ring,29. Thus, a circuitis completedfrom onesideof the power-source.

through the terminal .18, cartridge fuse. 6.7, sleeve. clip 54. and. terminal; 25 to thez circuit being;protected,. the

To insure good electrical. contact between, the.

4,. cartridge fuse 67 protecting the circuit. Another circuit is completed from the same side ofthe power source through the terminal 18, cartridge fuse 67, central contact 65 and sleeve contact 63 of the lamp 62, contact sleeve 48, contact ring 28, resistor 29 and terminal 22 to the other side of the source. of power. Since the resistance value of the resistor 29 is relatively low, the lamp 62;. which.is connected. inseries withuthe'cartridge fuse 67, is brightly illuminatedwhen electrical power is being. supplied to the circuit. being protected. This bright illumination of the lamp 62' passesthrough. the light transmitting part 57 so that the lamp 62.. here operates as a pilot lamp for indicating this condition. Another circuit" is completed from the same sid'e of the source of power through the terminal '18, resistor 32 and the clip 26 of the terminal 25, in shunt with the cartridge fuse 67, through the lamp 62, resistor 29 and terminal 22 to theother side of thepower. source since;the.. cartridge fuse is. in. shunt with the: resistor 32. This. last mentioned. circuit has no elfect. so long as the, cartridge fuse. is not blown. When, however, the.

cartridge; fuse67 blows the resistor 32, is connectedinseries. with, the. lamp 62 and the resistor 29 to. dimlyall. thatis. necessary is to remove the knob member 12- and. in so, doing, the... cartridge fuse. 67 is extracted from the. body member 11 when the knob member is re.- moved; There are no exposed live. parts so that the possibility of electrical shock is eliminated. The only exposed part, the. contact ring 28, is connected through the resistor 29 so. that the contact ring 28' is not hot. If the lamp 72' should become inoperative, it may be readily. replaced by merely separating the. part 57 from the remaining. parts. of the knob member 12, this of course, being done after. the. knob member 12 has been removed from the body member 11. When the. knob member. 1 2 isscrewed into the body member 11' to complete the aforementioned'ci'rcuits, the O-ring 42- is compressedfto. seal the inside of the fuse post against moisture anddirt.

While. for purposes of illustration, one form of' this invention has been disclosed other forms thereof may become apparentto those skilled in: the art upon reference to this disclosure. and, therefore. this invention is to be limited only by the scope of the append'edclai'rns.

I claim as my invention:

1'. A combined indicating fuse post and pilot lightv comprising, first and second, terminals for, electrical connection to opposite sides ofan electricalpower source, a third. terminal for electrical connection to the circuit beingprotected; a cartridge fuse, a lamp having a pair of. contacts,,one of said lamp contacts being electrically connected to one end of the. cartridge fuse, means for electrically connectingthe other'endofthe cartridge fuse to saidfirst terminal, means for electrically connecting said onezend of thecartridge. fuse to saidthird terminal to connect said cartridge fuse in series with the circuit being protected" to protect the same, means-including a resistor'for electrically connecting the other. lamp contact-to said second terminal for connecting the cartridge fuse andJamp in series to brightly illuminatesaid lamp when electrical, power, is being supplied" to the circuit.

being protected, andmeans including a resistor for..electrically connecting said first and third terminals. to. dimly illuminate said lamp upon blowing of saidlcartridgefusc.

2. A combinedindicating fuse post and-pilot light comprising. a. body. member constructed. to be. carried. by a panel and. having first. and second: terminals .for. electrical connection tmthe opposite sides-of an electrical power source: and.v a: third. terminal! for electrical connection to.

the circuit being protected, a cartridge fuse, a lamp having a pair of contacts, a knob member removably carrying the cartridge fuse and the lamp with one of the lamp contacts electrically connected to one end of the cartridge fuse, means for removably securing the knob member to the body member, means operative upon removably securing the knob member to the body member for electrically connecting the other end of the cartridge fuse to said first terminal, means operative upon removably securing the knob member to the body member for electrically connecting said one end of the cartridge fuse to said third terminal to connect said cartridge fuse in series with the circuit being protected to protect the same, means operative upon removably securing the knob member to the body member and including a resistor for electrically connecting the other lamp contact to said second terminal for connecting the cartridge fuse and lamp in series to brightly illuminate said lamp when electrical power is being supplied to the circuit being protected, and means including a resistor for electrically connecting said first and third terminals to dimly illuminate said lamp upon blowing of said cartridge fuse.

3. A combined indicating fuse post and pilot light comprising, a body member constructed to be carried by a panel and having first and second terminals for electrical connection to the opposite sides of an electrical power source and a third terminal for electrical connection to the circuit being protected, a cartridge fuse, a lamp having a sleeve contact and a central contact, a knob member removably carrying the cartridge fuse and the lamp in end to end alignment with one end of the cartridge fuse electrically contacting the central contact of the lamp, means for removably securing the knob member to the body member, means operative upon removably securing the knob member to the body member for electrically connecting the other end of the cartridge fuse to said first terminal, means operative upon removably securing the knob member to the body member for electrically connecting said one end of the cartridge fuse to said third terminal to connect said cartridge fuse in series with the circuit being protected to protect the same, means operative upon removably securing the knob member to the body member and including a resistor for electrically connecting the sleeve contact of the lamp to said second terminal for connecting the cartridge fuse and lamp in series to brightly illuminate said lamp when electrical power is being supplied to the circuit being protected, and means including a resistor for electrically connecting said first and third terminals to dimly illuminate said lamp upon blowing of said cartridge fuse.

4. A combined indicating fuse post and pilot light comprising, a body member constructed to be carried by a panel and having first and second terminals for electrical connection to the opposite sides of an electrical power source and a third terminal for electrical connection to the circuit being protected, a cartridge fuse, a lamp having a sleeve contact and a central contact, a knob member removably carrying the cartridge fuse and the lamp in end to end alignment with one end of the cartridge fuse electrically contacting the central contact of the lamp, means for removably securing the'knobmember to the body member, means operative upon removably securing the knob member to the body member for electrically connecting the other end of the cartridge fuse to said first terminal, means operative upon removably securing the knob member to the body member for electrically connecting said one end of the cartridge fuse to said third terminal to connect said cartridge fuse in series with the circuit being protected to protect the same, means operative upon removably securing the knob member to the body member and including a resistor for electrically connecting the sleeve contact of the lamp to 'said second terminal for connecting the cartridge fuse and lamp in series to brightly illuminate said lamp when electrical power is being supplied to the circuit being protected, and means including a resistor for electrically connecting said first and third terminals to dimly illuminate said lamp upon blowing of said cartridge fuse, and a spring carried by the body member for engaging said other end of the cartridge fuse when the knob member is removably secured to the body member for forcing said one end of the cartridge fuse against the central con tact of the lamp.

5. A combined indicating fuse post and pilot light comprising, a substantially cylindrical hollow body member formed of electrical insulating material and closed at its inner end and open at its outer end, first and second electrical terminals extending through the closed inner end of the body member for electrical connection to opposite sides of an electrical power source, a third terminal extending through the closed inner end of the body member for electrical connection to the circuit being protected, a contact ring carried by the body member at the open outer end thereof, means including a resistor for electrically connecting said second terminal to the contact ring, a clip on said third electrical terminal intermecliate the ends of the body member, a clip on said first electrical terminal adjacent the closed inner end of the body member, a resistor electrically connected between said first and third terminals, a cartridge fuse, a lamp having a sleeve contact and a central contact, a substantially cylindrical hollow knob member formed of electrical insulating material and having a contact sleeve and a sleeve clip, said lamp being removably secured in the contact sleeve with its sleeve contact electrically contacting the contact sleeve, one end of said cartridge fuse being removably secured in said sleeve clip in electrical contact therewith and with the central contact of said lamp, the other end of said cartridge fuse projecting from the knob member, and means for removably securing the knob member to the body member with said other end of the cartridge fuse electrically contacting the clip of the first terminal, with said sleeve clip electrically contacting the clip on said third terminal and with said contact sleeve electrically contacting said contact ring to connect said cartridge fuse in series with the circuit being protected to protect the same, to connect said cartridge fuse and lamp in series to brightly illuminate said lamp when electrical power is being supplied to the circuit being protected, and to connect said first mentioned resistor in series with said lamp to dimly illuminate said lamp upon blowing of said cartridge fuse.

6. A combined indicating fuse post and pilot light comprising, a substantially cylindrical hollow body member formed of electrical insulating material and closed at its inner end and open at its outer end, first and second electrical terminals extending through the closed inner end of the body member for electrical connection to opposite sides of an electrical power source, a third ter minal extending through the closed inner end of the body member for electrical connection to the circuit being protected, a contact ring carried by the body member at the open outer end thereof, means including a resistor for electrically connecting said second terminal to the contact ring, a clip on said third electrical terminal intermediate the ends of the body member, a clip on said first electrical terminal adjacent the closed inner end of the body member, a resistor electrically connected between said first and third terminals, a cartridge fuse, a lamp having a sleeve contact and a central contact, a substantially cylindrical hollow knob member formed of electrical insulating material and having a contact sleeve and a sleeve clip, said lamp being removably secured in the contact sleeve with its sleeve contact electrically contacting the contact sleeve, one end of said cartridge fuse being removably secured in said sleeve clip in electrical contact therewith and with the central contact of said lamp, the other end of said cartridge fuse projecting from the knob member, and means for removably securing the knob member to the body member with said other end of the cartridge fuse electrically contacting the clip of the first terminal, with said sleeve clipelectrically contacting the clip on said third terminal and with said contact sleeve electrically contacting said contact ring to connectsaid cartridge fuse in series with the circuit being protected to protect the same, to connect said cartridge fuse and lamp in series to brightly illuminate said lamp when electrical power is being supplied to the circuit being protected, and to connect said first mentioned resistor in series with said lamp to dimly illuminate said 'lampupon blowing of said cartridge fuse, and la spring interposed between the closed inner end of the body member and said other endof the cartridge fuse when the knob member is removably secured to the body member for forcing said one end of the cartridge fuse against the central contact "of the lamp.

7. A combined indicating Ifuse post and pilot light comprising, :a substantially cylindrical hollow body member formed of electrical insulating material and closed at its inner end and open at its outer end, first and second electrical terminals extending through the closed inner end of the body member for electrical connection to opposite sides of an electrical power source, a third terminal extending through the closed inner end of the body member for electrical connection to the circuit being protected, a contact ring carried by the body member at the open outer end thereof, means including a resistor for electrically connecting said second terminal to the contact ring, a clip on said third electrical terminal intermediate the ends of the body member, a clip on said first electrical terminal adjacent the closed inner end of the body member, a resistor electrically connected between said first and third terminals, a cartridge fuse, a lamp having a sleeve contact and a central contact, a hollow knob member formed of insulating material and including two-separable parts, one of said parts having a contact sleeve and a sleeve clip, said lamp being removably secured in the contact sleeve with its sleeve contact electrically contacting the contact sleeve and being enclosed by the other part of the knob member, one end of said cartridge fuse being removably secured in said sleeve clip in electrical contact therewith and with-the central contact of said lamp, the other end of said cartridge fuse projecting from the knob member, and means for removably securing the knob member to the body member with said other end of the cartridge fuse electrically contacting the clip of the first terminal, with said sleeve clip electrically contacting the clip on said third terminal and with said-contact sleeve'electrically contacting said contact ring to connect said cartridge fuse in series with the circuit being protected to protect the same, to connect said cartridge fuse and lamp in series to brightly illuminate said lamp when electrical power is being supplied to the circuit being protected, and to connect said first mentioned resistor in series with said lamp to dimly illuminate said lamp upon blowing of .said cartridge fuse.

8. In a combined indicatingfuse post and pilot light including a cartridge fuse for protecting an electric circuit and a lamp having a pair of contacts and which is brightly illuminated when electrical power is being supplied to the circuit being protected and which is dimly illuminated when the cartridge fuse .is blown, the improvement consisting of, first and second terminals for electrical connection to opposite sides of an electrical power source, a third terminal for electrical-connection to the circuit being protected, one of said lamp contacts being electrically connected to one end of the cartridge fuse, means for electrically connecting the'other end of the cartridge fuse to said first terminal, means for electrically connecting said one end of the cartridge fuse to saidthird'terminalto connectsaid cartridge fuse in series with the circuit being protected to protect the same, means including a resistor for electrically connecting the other lamp' contact to said second terminal "for connect- .8 1 ing' the cartridge fuse and lamp in series to brightly illuminate said rlamp when electrical power is being supplied tothe circuit being protected, and means including a resistor for electrically connecting said :first and third tormina'ls to dimly illuminatesaid lamp upon blowingof said cartridge fusev 9. :Inia combined indicating fuse post and pilot light including a cartridgefuse for protecting an electric circuit, a lamp having a pair of contacts and which :is brightly' illuminated when electrical power is being supplied to the circuit being protected "and which is dimly illuminated when the cartridge fuse is blown, a body member constructed to be carried by a panel and a knob member removably carried by the body member, the improvement :consisting of, first and second terminals carried by the body member for electrical connection to the opposite sides of an electrical power source, a third terminal "carried by the body member for electrical connection to'the circuit beingprotected, said -knob member removably carrying the cartridge 'fuse and the lamp :with one of the lamp contacts electrically connected to one end of the cartridge fuse, means operative upon removably securing the :knob member to the body member for electrically connecting 'the other end of the cartridge fuse to said first terminal, means operative upon removably securing the knob "member to the body member for electrically connecting said one end of the cartridge fuse to said third terminal to connect said cartridge fuse in series with the circuit being protected to protect the same, means OPCFEIlZlVB'UPYOD :removablysecurin'g the knob member to the body member and including a resistor for electrically connecting the'other lamp contact to said second terminal for connecting the cartridge fuse and l'ampin series to brightly illuminate said lamp when electrical power :is :being supplied to the circuit being uprotected,-and.=means including aresistor for electrically connecting 'saidfirst and third terminals to dimly illuminate said .lamp upon blowing of said :cartridge fuse.

10. In a 'combinedindicating fuse post and pilot light including-a cartridgefuse forprotecting an electric circuit, a lamp having-a .sle'eve contactand a central contact and which 'is brightly illuminated when electrical power is being supplied to the circuit being protected and which is dimly -.illurninated when the cartridge fuse is blown,

' a bodymember constructed to be carried by a panel and a knob member removably carried by the body member, the improvementconsisting of, first and second terminals carried by the body member for electrical connection to the opposite :sides of an electrical power source, a third terminal carried by the body member for electrical connection to the circuitbeingprotected, said knob member removably carrying the cartridge fuse and the :lamp in end to .end alignment with one 'end of the cartridge fuse electrically contacting the central contact of the lamp, means operative upon removably-securing the knob member "to the body member for electrically connecting the other end of the cartridge fuse to said first terminal, means voperative .upon removahly securing the knob member'to the body member for electrically connectingsaid one end of the cartridge fuse to said third terminal to connectsaidcartridge fuse .in series with the circuit being protected to protect the same, means operative upon removably securing:the knobtrnernber to the body member'and including a resistor for electrically connecting the sleeve contact of the lamp to said second terminal for connecting the cartridge fuse and lamp in series to brightly illuminate said lamp when electrical power is being supplied to the circuit being protected, and means including a resistor for electrically connecting said first and third terminals to dimly illuminate said lamp upon blowing of said cartridge fuse.

.111. In a'combined indicating fuse'post and pilotlight includingza cartridge fuse for protecting an electric circuit,alamphavingazsleeve contact and a central contact and "which is brightly illuminated when electrical :power is being supplied to the circuit being protected and which is dimly illuminated when the cartridge fuse is blown, a body member constructed to be carried by a panel and a knob member removably carried by the body member, the improvement consisting of, first and second terminals carried by the body member for electrical connection to the opposite sides of an electrical power source, a third terminal carried by the body member for electrical connection to the circuit being protected, said knob member removably carrying the cartridge fuse and the lamp in end to end alignment with one end of the cartridge fuse electrically contacting the central contact of the lamp, means operative upon removably securing the knob member to the body member for electrically connecting the other end of the cartridge fuse to said first terminal, means operative upon removably securing the knob member to the body member for electrically connecting said one end of the cartridge fuse to said third terminal to connect said cartridge fuse in series with the circuit being protected to protect the same, means operative upon removably securing the knob member to the body member and including a resistor for electrically connecting the sleeve contact of the lamp to said second terminal for connecting the cartridge fuse and lamp in series to brightly illuminate said lamp when electrical power is being supplied to the circuit being protected, and means including a resistor for electrically connecting said first and third terminals to dimly illuminate said lamp upon blowing of said cartridge fuse, and a spring carried by the body member for engaging said other end of the cartridge fuse when the knob member is removably secured to the body member for forcing said one end of the cartridge fuse against the central contact of the lamp.

12. In a combined indicating fuse post and pilot light including a cartridge fuse for protecting an electric circuit, a lamp having a sleeve contact and a central contact and which is brightly illuminated when electrical power is being supplied to the circuit being protected and which is dimly illuminated when the cartridge fuse is blown, a substantially cylindrical hollow body member formed of electrical insulating material and closed at its inner end and open at its outer end, and a substantially cylindrical hollow knob member formed of electrical insulating material and removably carried by the body member, the improvement consisting of, first and second electrical terminals extending through the closed inner end of the body member for electrical connection to opposite sides of an electrical power source, a third terminal extending through the closed inner end of the body member for electrical connection to the circuit being protected, a contact ring carried by the body member at the open outer end thereof, means including a resistor for electrically connecting said second terminal to the contact ring, a clip on said third electrical terminal intermediate the ends of the body member, a clip on said first electrical terminal adjacent the closed inner end of the body member, a resistor electrically connected between said first and third terminals, a contact sleeve and a sleeve clip carried by the knob member, said lamp being removably secured in the contact sleeve with its sleeve contact electrically contacting the contact sleeve, one end of said cartridge fuse being removably secured in said sleeve clip in electrical contact therewith and with the central contact of said lamp, the other end of said cartridge fuse projecting from the knob member, and means for removably securing the knob member to the body member with said other end of the cartridge fuse electrically contacting the clip of the first terminal, with said sleeve clip electrically contacting the clip on said third terminal and with said contact sleeve electrically contacting said contact ring to connect said cartridge fuse in series with the circuit being protected to protect the same, to connect said cartridge fuse and lamp in series to brightly illuminate said lamp when electrical power is being supplied to the circuit being protected, and to connect said first mentioned resistor in series with said lamp to dimly illuminate said lamp upon blowing of said cartridge fuse.

13. In a combined indicating fuse post and pilot light including a cartridge fuse for protecting an electric circuit, a lamp having a sleeve contact and a central contact and which is brightly illuminated when electrical power is being supplied to the circuit being protected and which is dimly illuminated when the cartridge fuse is blown, a substantially cylindrical hollow body member formed of electrical insulating material and closed at its inner end and open at its outer end, and a substantially cylindrical hollow knob member formed of electrical insulating material and removably carried by the body member, the improvement consisting of, first and second electrical terminals extending through the closed inner end of the body member for electrical connection to opposite sides of an electrical power source, a third terminal extending through the closed inner end of the body member for electrical connection to the circuit being protected, a contact ring carried by the body member at the open outer end thereof, means including a resistor for electrically connecting said second terminal to the contact ring, a clip on said third electrical terminal intermediate the ends of the body member, a clip on said first electrical terminal adjacent the closed inner end of the body member, a resistor electrically connected be tween said first and third terminals, a contact sleeve and a sleeve clip carried by the knob member, said lamp being removably secured in the contact sleeve with its sleeve contact electrically contacting the contact sleeve, one end of said cartridge fuse being removably secured in said sleeve clip in electrical contact therewith and with the central contact of said lamp, the other end of said cartridge fuse projecting from the knob member, and means for removably securing the knob member to the body member with said other end of the cartridge fuse electrically contacting the clip of the first terminal, with said sleeve clip electrically contacting the clip on said third terminal and with said contact sleeve electrically contacting said contact ring to connect said cartridge fuse .in series with the circuit being protected to protect the same, to connect said cartridge fuse and lamp in series to brightly illuminate said lamp when electrical power is being supplied to the circuit being protected, and to connect said first mentioned resistor in series with said lamp to dimly illuminate said lamp upon blowing of said cartridge fuse, and a spring interposed between the closed inner end of the body member and said other end of the cartridge fuse when the knob member is removably secured to the body member for forcing said one end of the cartridge fuse against the central contact of the lamp.

14. In a combined indicating fuse post and pilot light including a cartridge fuse for protecting an electric circuit, a lamp having a sleeve contact and a central contact and which is brightly illuminated when electrical power is being supplied to the circuit being protected and which is dimly illuminated when the cartridge fuse is blown, a substantially cylindrical hollow body member formed of electrical insulating material and closed at its inner end and open at its outer end, and a substantially cylindrical hollow knob member formed of electrical insulating material and removably carried by the body member, the improvement consisting of, first and second electrical terminals extending through the closed inner end of the body member for electrical connection to opposite sides of an electrical power source, a third terminal extending through the closed inner end of the body member for electrical connection to the circuit being protected, a contact ring carried by the body member at the open outer end thereof, means including a resistor for electrically connecting said second terminal to the contact ring, a clip on said third electrical terminal intermediate the ends of the body member, a clip on said first electrical terminal adjacent the closed inner end 11 of the bodymember, a resistor electrically connected between said first and third terminal-s, said hollow knob member including two separable .parts, one of said parts having a contact sleeve and a sleeve clip, said lamp being removably secured in the contact sleeve with its sleeve contact electrically contacting the contact sleeve and being enclosed by the other ;part of the knob memher, one end of said cartridge fuse being rernovalbly secured in said'sleeve clip in electrical contact therewith and with the central-contact of said lamp, the other end of said cartridge fuse projecting from the knob member, and means for removably securing the knob @member to the body member with said other 'end of the cartridge fuse electrically contacting the clip of the first terminal, with .said sleeve clip electrically contacting :the clip-on said third terminal and with said contact sleeve electrically contacting said contact ring to connect said cartridge fuse in series with the circuit being protected ttO protectthe same, torconnect said cartridge fuse and lamp in series to brightly illuminate said lamp when electrical power is being supplied to the circuit being protected, and to connect said first mentioned resistor in series with said lamp to dimly illuminate said lamp upon blowing of said cartridge .fuse.

References Cited in the file of this patent UNITED STATES PATENTS 

